Cut-out for spark plug suppressors



Nov. 12, 1935. J. w. FITZ GERALD CUT-OUT FOR SPARK PLUG SUPPRESSORS 2Sheets-Shet 1 Filed Dec. s, 1935 mm WflizLm/d 1935- J. w. FlTZ GERALDCUT'OUT FOR SPARK PLUG SUPPRESSORS Filed Dec. 8, 1955 Patented Nov. 12,1935 UNITED STATES PATENT OFFICE 2,021,056 CUT-OUT FOR SPARK PLUGSUPPRESSORS John W. Fitz Gerald, Milwaukee, Wis., assignor toAllen-Bradley Company, Milwaukee, Wis., a corporation of WisconsinApplication December 8, 1933, Serial No. 701,422

3 Claims.

the spark plugs with suppressors to damp out these objectionableoscillations. sors are in the form of resistors a predetermined minimum.

This general object may be attained in difierout ways, but it ispreferable to provide each suppressor with an individual bridging memberarranged to electrically bridge the terminals of the suppressor.

With the above and other objects in view which will appear as thedescription proceeds, my invention resides in the novel construction,combihereinafter described and more particularly defined by the appendedclaims, it being understood that such changes in the precise embodimentof the herein disclosed invention may be made as come within the scopeof the claims.

In the accompanying drawings, I have illustrated two complete examplesof the physical embodiment of my invention to the best modes I have sofar devised for the practical application of the principles thereof, andin which:

Figure 1 is a side view of a suppressor equipped with one formofshort-circuiting means;

Figure 2 is a diagrammatic illustration of a conventional ignitionsystem illustrating the application of this invention thereto;

Figure 3 is a side view showing a modified form of short circuitingmeans in which the functioning thereof is in response to temperaturechanges;

Figure 4 illustrates another modified embodiment of the invention,wherein the blast of air induced by the fan of the engine is utilized toactuate the bridging member;

Figure 5 illustrates another manner of actuating the bridging member;

Figure 6 is a top view of an internal combustion engine illustrating theapplication of a number of suppressors equipped with bridging membersand common means to actuate all of the bridging members;

Figure 7 is a fragmentary view similar to Figure 6, showing a specificmanner of moving the common actuating means; and

Figure 8 is a section view through Figure 6 on the plane of the line8-8.

Referring now more particularly to the accompressors ID of anyconventional construction. A suppressor is also interposed in the leadto the distributor arm.

To overcome this objection, the present invention provides simple buteflicient means for short circuiting the resistance element byelectrically connecting the terminals of the suppressors through abridging member indicated generally by the numeral Hi.

In Figure 1, the bridging member I 6- consists of a strip of bi-metallicmetal I! having one end l8 secured to one terminal by the attachingmeans l4 and its other end l9 arranged to contact the other terminal l2.Normally, the bi-metallic strip I1 is in a position at which its end I9engages the adjacent terminal I2, thus short-circuiting the suppressorand affording a low resistance path directly to the spark plug.

To disengage the end H! from its terminal l2, a heater coil 20 isprovided. The coil may encircle the bimetallic strip or may be mountedin close proximity thereto. It

controls the supply of current from the battery 22 to the radio. Thecircuit for energizing the coil 20 is apparent from the drawings.

' having one end '28 A modification of the use of the bimetallic stripis illustrated in Figure 3. In this embodiment, a bimetallic strip 23 islooped back and forth to increase the range of movement of its free end24 in response to temperature changes. The opposite end 25 of the stripis secured by the attaching means M to the adjacent terminal l2 of thesuppressor, the free end 24 being arranged to move into and out ofengagement with the bracket 13, which is in electrical connection withthe adjacent terminal 12. In this embodiment, no external means areprovided for causing the bridging member to move to and from operativeposition, the desired motion being obtained entirely from the inherentcharacteristics of the bimetallic strip. During normal temperatures, thefree end 24 is spaced from the bracket [3, but when the temperaturedrops sufficiently low, the end 2d cont; cts the bracket and thusshort-circuits the suppressor.

In Figure 4, the bridging member is actuated pneumatically by the blastof air induced by the Ian 26 of the engine. For this purpose, the briding member is in the form of a metal strip 21 attached to the terminall2 at the mounting bracket l3. Opposite the other terminal the stripcarries a contact point 2:) to engage said other terminal. The inherentresiliency of the strip 2! normally holds the contact point 25 inengagement with the adjacent terminal.

Above the contact point 29, the strip carries a vane 30, which is in thedirect path of the blast of air emanating from the fan so that when theengine attains an operating speed, the bridging member will be moved toan inoperative position.

In Figure the bridging member is similar to that illustrated in Figure1, except that it is not formed of a bi-metallic metal, but ispreferably constructed of iron or steel. In its normal position, thebridging member has its free end disengaged from the adjacent suppressorterminal, and to engage the same and effect the shortcircuiting oi thesuppressor, an electromagnet 3| is mounted on the suppressor. Theelectromagnet is arranged to be energized simultaneously with theclosing of the starter switch 32 as is clearly evident from thedrawings. Consequently, during the starting cycle, the suppressor isshort-circuited.

Figure 6 illustrates a plurality of suppressors arranged in a row andsupported by their re spective spark plugs. Each of these suppressors isequipped with abridging member 33 in the form of a metal strip similarto that illustrated in Figure 5, having one end anchored to one of thesuppressor terminals and its other end arranged to contact the otherterminal.

The normal resiliency of the bridging members holds them in theiroperative short-circuiting positions, to move the same out of theirshort-circtiting positions, the shifter rod 34 is provided. The rod 34is slidably mounted by brackets 35 to traverse all of the suppressorsand is equipped with a plurality of cams 33, one for each suppressor,which upon longitudinal shifting of the rod in one direction, moves allof the bridging members to their inoperative positions. The shifter rod34 may be actuated manually or automatically.

If desired, the rod may be actuated by means of an electromagnet 31 asshown in Figure '7. The electromagnet 31, like the electromagnet 3|, inFigure 5, is arranged to be energized simultaneously with the closing ofthe starting switch 32. In this form of the invention, the cams arereversed from the positions shown in Figure 6, so that upon automaticactuation of the shifter rod by the electromagnet, the bridging membersare allowed to drop to their operative positions. A tension spring 38 isprovided to return the rod to its position holding the bridging membersin their inactive positions.

From the foregoing description taken in connection with the accompanyingdrawings, it will be readily apparent to those skilled in the art thatthis invention afiords simple means for obviating the difficulties ofstarting caused by the presence of the high resistance in the spark plugleads where a radio is installed in an automobile.

It is also readily apparent that while several different embodiments ofthe invention have been illustrated, and several means of actuating thebridging members to and from their operative positions are shown, theinvention is susceptible to other applications.

It is noted that in certain forms of the invention, especially thatembodiment illustrated in Figure 3, where the free end of the bridgingmember during normal operating conditions may be in a position close tothe bracket I3, but still not touching the same, the eflect of a sparkintensifier is obtained. This is an added advantage of the invention.

What I claim as my invention is:

1. In a suppressor of the character described and comprising a highresistance element, terminals for the high resistance element and asupporting structure for the element and terminals, a bridging memberelectrically connected with one of the terminals and movable to and fromelectrical connection with the other terminal, said bridging memberbeing thermally responsive and moving to and from its bridging positionin response to temperature changes thereat whereby the short circuitingof the high resistance element thereby is determined by the ambienttemperature.

2. In a suppressor of the character described and comprising a highresistance element, terminals for the high resistance element and asupporting structure for the element and terminals, a bi-metallic stripconnected to one of the terminals and having a part engageable with theother terminal to electrically bridge the terminals and shunt the highresistance element, said bi-metallic strip moving in response totemperature changes thereat whereby the short circuiting of theresistance element is determined by the ambient temperature.

3. In a suppressor of the character described and comprising a highresistance element, terminals for thehigh resistance element and asupporting structure for the element and terminals, a bimetallic striphaving one end secured to one of the terminals and its other endoverlying the other terminal and movable in response to changes in theambient temperature to and from a position electrically bridging theterminals and short-circuiting the high resistance element.

JOHN W. FITZ GERALD.

